Analysis of etiological characteristics of influenza B virus in Songjiang district, Shanghai from 2017 to 2020
10.3760/cma.j.cn112866-20220722-00164
- VernacularTitle:2017—2020年上海市松江区乙型流感病毒病原学特征分析
- Author:
Ling LIU
1
;
Jiajin WU
;
Xinyu XU
;
Xiajing YAO
;
Yonggen JIANG
;
Fengsong SHENG
;
Xuefei QIAO
Author Information
1. 上海市松江区疾病预防控制中心，上海 201620
- Keywords:
Influenza B virus;
Hemagglutinin;
Neuraminidase;
Genetic characteristics;
Neuraminidase inhibitors
- From:
Chinese Journal of Experimental and Clinical Virology
2022;36(6):671-677
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the prevalence of influenza B virus and its HA and NA genes characteristics during 2017—2020 in Songjiang district, Shanghai.Methods:Samples from suspected cases of influenza were detected using real-time fluorescence reverse transcription-polymerase chain reaction. Influenza B virus positive specimens were cultured by MDCK cells and embryonated chicken eggs. The hamagglutinin (HA) and neuraminidase (NA) genes of influenza virus B strains were sequenced and analyzed for gene evolution and amino acid variation. The sensitivity of the strains to oseltamivir and zanamivir was studied by neuraminidase inhibition assay.Results:The positive rate of influenza B virus in Songjiang district from 2017 to 2020 was 14.24% (506/3554). Influenza B virus circulated mainly in winter-spring season and alternated between B/Victoria and B/Yamagata subtypes. Subclade 1A (△3) B was the predominant Victoria lineage circulating in Songjiang district. Otherwise, the remaining strains belonged to subclade 1A(△2)and clade 1A. Compared with vaccine strain B/Brisbane/60/2008, the nucleotide homology of circulating strains HA (NA) was 97.62%~98.19% (98.11%~98.78%). The mutations of HA in 1A (△3) B subclade mainly were in 120 loop and 160 loop. All the Yamagata strains circulating in Songjiang district belonged to clade 3. Compared with vaccine strain B/Phuket/3073/2013, the nucleotide homology of HA and NA were 98.71%~99.04% and 98.69%~99.27%, respectively. No amino acid change was found in the antigenic clusters. Neuraminidase inhibition assay showed that the influenza B virus strains were sensitive to both oseltamivir and zanamivir.Conclusions:Inconsistence of the antigenicity between the vaccine strains and the circulating strains during 2017—2020, influenza B virus should be persistently monitored, including the epidemic situation and the etiological characteristics, which might be helpful in vaccine screening and drug development.
